Energy Dispersive X-ray Fluorescence Research Articles

Study of the Materials and Techniques of a Rare Papier-Mâché Mushroom Model Crafted in H. Arnoldi Factory.

The Natural History and Science Museum of the University of Porto houses a collection of 45 models of fungi in papier-mâché from the 19th-century, which were used at the university until 2015 as didactic models. For the first time, the materials and techniques used in the production of a Boletus edulis model were studied (vernacular name: cep, porcini). These sculptures, made to life-size scale, are painted in colors similar to those of the represented species (white, brown, and light brown). They are fixed to a rectangular base, which is painted black, and to which moss has been pasted. To fully characterize each color, at the molecular level, a multi-analytical approach was used, combining energy-dispersive x-ray fluorescence spectroscopy (micro-XRF) with fingerprinting techniques of Raman microscopy (microRaman and handheld Raman) spectroscopy and microFourier transform infrared spectroscopy (microFTIR). The papier-mâché was prepared with a groundwood paper to which kaolin and a quartz-based material have been added to reinforce the structure. Raman microscopy also identified carbon black in it, which is possibly responsible for its grey color. The white color was unequivocally identified as lithopone by microRaman. This white paint was prepared in a proteinaceous tempera, with calcium carbonate having been identified as filler (by microFTIR). In the brown color, iron was identified by microXRF, pointing to the use of ocher, which was not possible to identify by microRaman and microFTIR. Regarding the black rectangular base, the moss was fixed using a collagen-based glue. The binding medium in this black is possibly a mixture of drying oil and protein. Again, XRF detected iron as the main element, but it was not possible to acquire a Raman spectrum due to the high fluorescence of the binder/varnish. Others, such as the writing inks, will also be discussed. The colors identified are in line with the best materials available for use by artists of that time. This new knowledge is fundamental to informing the choice of the best conservation strategies for the preservation of these extraordinary models.

Spectral Lines of Ca<sup>2+</sup>, Au<sup>3+</sup>, and Ag<sup>+</sup> Found in Complex Matrices and Interactions of These Ions with Molecules, Cells and Mineral Surfaces

Energy Dispersive X-Ray Fluorescence (EDXRF) is a non-destructive analytical method used to solve problems involving nutritional, mineral, and toxic chemical elements. It is very common in the customization and commerce of jewelry. EDXRF depends on recording spectral lines from the irradiation of isotopes. After a brief review of the interactions of the ions Ca²⁺, Zn²⁺, P, Au³⁺, and Ag⁺ along with the results of the current study it was revealed that the methodology, when used in a semi-quantitative approach, can successfully identify all elements present in a whalebone sample collected from Santa Catarina Island (Brazil). This article serves as an example to explain the molecular reactions of Ca²⁺ and the concentration of elements: Cl^-, Zn²⁺, Br, Fe, Mn, Ca, K, S, P, and Si. It was proposed initially to evaluate spectral lines of Ca²⁺ found in the whalebone (biomarker). The model was then further expanded to explore Ca²⁺ and its relationships to the intra- and extracellular environments, where the plasma membrane Ca²⁺-pump (PMCA) is responsible for Ca²⁺ ejection in most eukaryotic, excitable cells as, eg, in the cardiac tissue with a Na/Ca exchanger. The certified Road Dust (BCR-723, which is in prominence among the reference materials used) could be applied to samples of dust, soils, sediments, fossil fuel, ceramic, and bio-ceramic in general. With the aid of a matching matrix, it has been shown that EDXRF can function even with samples of Au³⁺ and Ag⁺. The results with certified reference samples of Road Dust (BCR-723) and its standards serve as a basis for studies of catalyst supports, an eg aluminum oxide containing titanium, erbium, lanthanum, and other elements, and as a model of charged ions.

Critical Analysis of the Materials Used by the Venetian Artist Guido Cadorin (1892–1976) during the Mid-20th Century, Using a Multi-Analytical Approach

The present study sought to expand on and confirm the already available information on the painting materials used by the Venetian artist Guido Cadorin (1892–1976). A multi-analytical approach was employed in the study of six tempera grassa easel paintings and one casein tempera on a panel signed by the artist and belonging to the International Gallery of Modern Art Ca’ Pesaro in Venice, Italy, which dated from 1921 to 1951. The aim of the research was to identify the painting materials, observe the evolution of the color palette through time and assess the state of conservation. Non-invasive imaging and/or spectroscopic techniques were employed, such as hyperspectral imaging spectroscopy (HSI) and Raman spectroscopy. Microsamples were also collected from the edges and detached areas of the canvases that were studied through three non-destructive techniques, namely optical microscopy (OM), energy dispersive x-ray fluorescence spectrometry (EDXRF) and attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), and one destructive technique, namely gas chromatography-mass spectrometry (GC/MS). The results allowed the inference of the color palette used to render the artist’s paints, composition of the preparation layer, and characterization of the binding media and varnish layers. Moreover, the state of conservation of the artworks was determined. Thus, the outcome of this research enriches the painter’s profile and might aid the International Gallery of Modern Art Ca’ Pesaro in Venice, Italy in the planning of future conservation treatments in accordance with the guidelines of good practices in art conservation.

Evaluating possible prehistoric cave art in the central Mediterranean: Analyses of pigment traces and identification of taphonomic processes at Għar Ħasan, Malta

The archaeology of the Maltese Islands, particularly the megalithic ‘temple’ structures and underground mass burial sites (hypogea) of the ‘Temple Period’ (ca. 3800 – 2300 BCE), has been the subject of considerable interest. Less is known about the prehistoric use of caves. In particular reports of prehistoric cave art at Għar Ħasan (Hasan’s Cave) have remained controversial, and have been argued to reflect an otherwise unknown pre-Neolithic occupation on the islands.Here, we report a reinvestigation of Għar Ħasan. To distinguish graffiti that have accumulated over the last century and possible older rock art, a range of non-invasive methods were used to determine the chemical properties and colour spectrum of the pigment traces: portable energy-dispersive X-ray fluorescence spectrometry (p-ED-XRF) and visible (VIS) and near-infrared (NIR) spectroscopy. In addition, pigment traces were analyzed with digital microscopy and image enhancement techniques (DStretch).Most of the previously reported cave paintings were shown to have been produced in the last century. One key panel may be older, but vandalism and other destructive processes make a definitive assessment challenging. While we therefore consider the evidence for ‘Palaeolithic’ cave art at Għar Ħasan to be inconclusive, our study also identified complex taphonomic processes that pose severe limitations on the identification of pigment via p-ED-XRF and spectroscopy and can inform and guide future initiatives for rock art conservation.

Antifungal activity of silver nanoparticles prepared using Aloe vera extract against Candida albicans.

Resistance to antifungal agents is a serious public health concern that has not been investigated enough because most studies on antimicrobials are dedicated to antibacterial resistance. This study aimed to synthesize silver nanoparticles (AgNPs) using Aloe vera extract, and to assess its antifungal activity against Candida albicans. Silver nanoparticles were synthesized by reducing Ag nitrate with aqueous A. vera extracts. Physicochemical properties of synthesized AgNPs were determined by ultraviolet-visible spectrophotometry, photon cross-correlation spectroscopy, energy-dispersive X-ray fluorescence spectrometry, X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. An antifungal investigation was performed against four clinical C. albicans (C1, C2, C3, and C4) and a reference strain, C. albicans ATCC 10321. Cubic AgNPs with a mean X50 hydrodynamic diameter of 80.31 ± 10.03 nm were successfully synthesized. These AgNPs exhibited maximum absorbance at 429.83 nm, and X-ray fluorescence (XRF) confirmed the presence of Ag in AgNPs solution by a characteristic peak in the spectrum at the Ag Kα line of 22.105 keV. Infrared spectra for AgNPs and A. vera extract indicated that the compounds present in the extract play an essential role in the coating/capping of synthesized AgNPs. Different concentrations (200, 100, 50, 25, 10, and 5 μg/mL) of AgNPs were tested. The antifungal activity was shown to be dose-dependent with inhibition zones ranging from 10 mm to 22 mm against C. albicans ATCC 10231, 0 mm to 15 mm against C1, 0 mm to 16 mm against C2 and C3, and 0 mm to 14 mm for C4. Minimum inhibitory concentration ranged from 16 μg/mL to 32 μg/mL against clinical C. albicans (C1, C2, C3, and C4) and was 4 μg/mL against C. albicans ATCC 10231. This study showed the ability of A. vera to serve as an efficient reducing agent for the biogenic synthesis of AgNPs with excellent antifungal activity.

Quality evaluation and energy dispersive X-ray fluorescence analysis of commercial samples of chamomile in the city of Lavras - MG, Brazil

Quality evaluation and energy dispersive X-ray fluorescence analysis of commercial samples of chamomile in the city of Lavras - MG, Brazil

Technical note: Validation of energy dispersive X-ray fluorescence for determination of indigestible markers in ruminant fecal and rumen fluid samples.

Determination of digestibility and passage rate is important for further understanding of nutrient utilization and thereby aids in improving nutrient utilization efficiency. Titanium dioxide and chromium ethylenediaminetetraacetic acid are commonly used as indigestible markers for determining passage rates of diets to aid in determination of digestibility. Analyzing Ti and Cr involves the use of procedures such as acid digestions, inductively coupled plasma spectroscopy, and atomic absorption. These commonly used methodologies involve hazardous chemicals, destruction of samples, and low sample throughput. The objective of this experiment was to develop and validate an accurate and precise method for measuring both Ti and Cr using energy dispersive X-ray fluorescence (ED-XRF). Energy dispersive X-ray fluorescence is an analytical technique used for analyzing elements in various sample types. The samples were added to the ED-XRF machine and irradiated with X-rays. The intensity of the X-rays emitted (termed fluorescent X-rays) was used for calculation of the concentration of the element. The method for Ti was constructed using fecal samples from cattle consuming three different diet types (finishing diet, dairy lactation diet, and grazing native range pasture). The Cr method was developed for rumen fluid analysis. We compared the machine-calculated concentrations of each element to the concentration calculated by a standard curve. For both the Ti and Cr, the standard curve-calculated value had a lower percent difference overall at 4.56% and 12.59%, respectively, compared to the machine percent difference of 8.35% and 16.38% for Ti and Cr, respectively. To determine accuracy and precision of the method, samples were spiked with various amounts of Ti or Cr and measured for their respective compounds with percent recovery and inter- and intra-assay CV-calculated thereafter. The average recovery for Ti across all diet types was 100.3%, and the recovery for Cr in rumen fluid was 95.7%. The average inter- and intra-assay CV for Ti, across all diet types, were 9.70% and 2.16%, respectively. For Cr, the average inter- and intra-assay CV were 5.42% and 8.45%, respectively. The ED-XRF method requires minimal additional chemicals, is cost-effective, and allows for sample preservation as well as a high throughput of samples. Our results indicate utilization of ED-XRF is an accurate and precise method for determination of Ti in feces and Cr in rumen fluid.

Rapid screening of pharmaceutical products for elemental impurities by a high-resolution portable energy dispersive X-ray fluorescence spectrometer using an efficient fundamental parameter method.

In this study, a rapid screening method for elemental impurities in pharmaceutical products has been established by portable energy dispersive X-ray fluorescence (EDXRF) spectroscopy combined with the efficient fundamental parameter method. The proposed method has been used for the screening of 22 elemental impurities (i.e., Cd, Pb, As, Hg, Co, V, Ni, Tl, Au, Pd, Ir, Os, Rh, Ru, Se, Ag, Pt, Sb, Mo, Cu, Sn, and Cr) in the International Conference on Harmonization (ICH) Q3D guideline. The verification of results could meet the acceptance criteria for accuracy, precision and linearity in the United States Pharmacopoeia 〈233〉. On the other hand, the limit of quantitation of the proposed EDXRF method for the screening of 22 elemental impurities in pharmaceutical products could meet the concentration limits of each element at 10 g maximum daily intake based on the established permitted daily exposure to oral drugs in the ICH Q3D guideline. Our findings open up new possibilities in the rapid screening of pharmaceutical products for the detection of elemental impurities by EDXRF, which can be expected to provide a novel, nondestructive, high-throughput, portable, and sensitive platform for the process control of elemental impurities to ensure the quality and safety of drugs.

PRINCIPAL COMPONENT ANALYSIS (PCA) PARA A AVALIAÇÃO DE DADOS QUÍMICOS E GERAÇÃO DE HEAT MAPS: UM TUTORIAL

PRINCIPAL COMPONENT ANALYSIS (PCA) FOR CHEMICAL DATA EVALUATION AND HEAT MAPS PREPARATION: A TUTORIAL. This tutorial shows a step-by-step guide on handling big datasets using principal component analysis (PCA). A dataset of chemical elements, concentration, emission spectrum, and energy-dispersive X-ray fluorescence (EDXRF) of e-waste were used as examples. Five routines were proposed to apply data processing and PCA calculation focusing data from laser-induced breakdown spectroscopy (LIBS), EDXRF, and heat maps preparation. These routines can be used in various softwares such as MatLab, Octave, R, and Python. PCA was applied in three examples; the first was for concentrations, and the other two were for spectra. An example of heat maps assembling a hyperspectral image of a printed circuit was also described. In addition, a playlist was created on YouTube using the available examples. Therefore, with this tutorial, it may be possible to learn how to deal with a large volume of data by applying PCA. The authors hope to contribute to those researching in the area.

Petrographic Characteristic and Geochemical features of Basement Rocks in Ikogosi, Southwestern Nigeria.

This study investigates and reports petrographic characteristics, geochemical features and the processes of formation of rocks in Ikogosi, southwestern Nigeria. Eighteen (18) rock samples (six quartzite, six migmatite gneiss and six schists) were collected and subjected to optical study. Ten (10) representative samples (six quartzite, three schist and one migmatite gneiss) were evaluated for major elements composition using Energy Dispersive X-Ray Fluorescence (ED-XRF). Petrographic evaluation revealed quartz, feldspar, muscovite, biotite, hornblende, pyroxene and opaque are dominant mineral constituents in quartzite and schist while migmatite gneiss contains the same set of minerals but without opaque constituents. Quartz forms a dominant constituent in quartzite and migmatite gneiss but as subordinate mineral in the schist. The feldspars are mainly plagioclase with albite twinning, associated microcline has characteristic crosshatched twinning. Chemical investigation reveals the rock units are generally siliceous. Three oxides (SiO2, Al2O3 and Fe2O3) constitute 85–90% of the bulk chemical composition of the rocks. SiO2 constituent as applied in rock classification indicates the quartzite is unequivocally felsic, migmatite is intermediate while the schist is mafic to ultramafic. K2O versus SiO2 variation plot revealed that the quartzite and schist are tholeiitic while the migmatite gneiss is shoshonitic. TiO2 versus SiO2 variation diagram depicts igneous antecedent.

Estimation of Heavy Metals Content at Traffic Inter-Change Ita-Marun Epe Lagos State Nigeria

This study assesses the vehicular and traffic emission at Ita-marun Epe Lagos State. Road traffic area contains contaminants which affects human, animals and plants. Hence, the need to investigate the concentrations of these contaminants within the selected area. Three deposition gauges of 0.15 by 0.20 mm were planted at selected sampling site for 30 days between December 2021 and January 2022. The Lagos State University Epe campus was used as the control experiment for this research work. Deposition flux for each site was determined. The contaminants levels of the heavy metals in particulate matter were evaluated using the Enrichment Factor (EF) analysis. Deposition fluxes determined range from 31.8269-39.7836 g/m2/month at the sampling site while it ranges 42.3934-51.0567 g/m2/month at control site. Elemental analyses of all the samples collected were determined using the Energy Dispersive X-ray Fluorescence (EDXRF). EF reveals that 7 elements Ag, Cd, Cr, In, Mn, Sn, and Zn are highly enriched at sampling site while 6 elements S, Cl, Zn, Ge, As and W at the control site respectively. Results shows that fluxes at the control site were higher than that of the sampling site. EF also reveals that seven elements at the sampling site and six elements at the control site were anthropogenically derived. Due to the findings of this research, a clean-up of this area is highly recommended.

Accuracy and Precision of Energy Dispersive X-Ray Fluorescence (EDXRF) Analysis of Trace and Major Elements in Rock Standard Reference Materials Using Fine Powder

Accuracy and Precision of Energy Dispersive X-Ray Fluorescence (EDXRF) Analysis of Trace and Major Elements in Rock Standard Reference Materials Using Fine Powder

Climate-smart aquaculture in Tanzania: Assessment of transitional and heavy metals concentrationsin a commonly used local feed ingredientfor Tilapia farming

A study conducted from January through May 2023 toassess the concentrations of heavy and transitional metals in a commonly used local feed ingredientin a farmed Nile tilapia diet (Oreochromis niloticus) in Tanzania. Eleven fish feed ingredients such as, sunflower seed cake (SFSC), wheat pollard (WP), maize bran (MB), fish meal (FM), freshwater shrimp (FWS), cattle blood meal (CBM), bone meal (BM), soya bean meal (SBM), and rice bran (RB), brewers’ spent grain (BSG) and Taro leaves (Colocasia esculenta; TL) were randomly sampled from feed manufacturers, animal feeds’ centers and other animal feeds suppliers inArusha and Dar es Salaam region for inclusion in this study. Heavy metals and transition metals in feed ingredients were analyzed using the Energy-Dispersive X-rays Fluorescence (XRF) (Xla Pro-Spectrometer/German) at the Tanzania Atomic Energy Commission(TAEC) laboratory. The results showed that most of the fish-feed ingredients used in this study comply with the maximum allowable concentrations in Nile tilapia diets-according to the Tanzania bureau of standards and the European commission. However, the results showed that, the concentrations of reported metals (As, Pb, Cd, Hg, Co, Cu, Mo, Mn, Ni, Ag, V, Cr, Fe and Zn) varied significantly (p < 0.05 ) in most of the analyzedlocal feed ingredients collected in Tanzania. The study has paved the way for other researchers to further assess more feed ingredients used not only on heavy metals but other potential contaminants in feeds to ensure sustainable fish farming in Tanzania

Ocorrência de laminite clínica após adaptação ao confinamento: efeitos na morfologia, densidade e composição mineral do casco de bovinos Nelore após terminação

ABSTRACT: Laminitis is a disease that affects the dermis and epidermis of the bovine hoof, generating changes in the hoof capsule. This study evaluated the effects of clinical laminitis diagnosed after the adaptation phase to confinement on the morphology, density, and mineral composition of the hoof of Nellore cattle after finishing. The animals were separated in the first weeks of confinement into a sick group (SG), with clinical laminitis, and a healthy group (HG). SG animals had higher heel length, dorsal wall length, toe height, and diagonal hoof length (p<0.05) than healthy animals. The dermal laminae had similar measurements for thickness, length, and spacing between them between SG and HG. Animals with laminitis showed congestion, hemorrhage, and basement membrane irregularities on histology. Computed microtomography (μCT) revealed that the hoof density of sick animals is lower than healthy ones. According to the mineral composition by energy-dispersive X-ray fluorescence (ED-XRF) spectrometry, the hooves of animals with laminitis (SG) and healthy ones (HG) were not biochemically different. Therefore, the occurrence of clinical laminitis in Nellore cattle in the first weeks of confinement causes an increase in the morphometric parameters of the hoof capsule and a reduction in the density of the abaxial hoof wall evaluated after the finishing period. This disease does not promote changes in the histomorphometric parameters of the dermal laminae and the percentage of minerals in the abaxial hoof wall.

Fluorine-free organic electrolytes for the stable electrodeposition of neodymium metal.

Electrowinning is regarded as a clean process to recover neodymium metal from secondary sources such as spent Nd-Fe-B permanent magnets, but the current methods are severely limited by a high energy consumption (molten salts), or by the high costs and environmental impact of the electrolyte components (ionic liquids). Therefore, there is a demand for more sustainable electrowinning methods for the recovery of neodymium metal. Inspired by our own previous work and the work of others, we developed new fluorine-free organic electrolytes that enable the electrodeposition of neodymium metal at room temperature. The electrolytes consist of solvated neodymium borohydride, Nd(BH4)3, dissolved in the ether solvents tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1,2-dimethoxyethane (DME) and diethylene glycol dimethyl ether (diglyme, G2), and these complexes can be prepared entirely from non-fluorinated precursors such as neodymium(III) chloride (NdCl3) and sodium borohydride (NaBH4). In contrast to our previous bis(trifluoromethylsulfonyl)imide-containing electrolytes, electrodeposition of neodymium proceeds over time without significant loss of current density, indicating a higher stability against unwanted side-reactions that lead to passivation of the deposit on the electrode. Characterization of the deposits by scanning electron microscopy (SEM), energy-dispersive X-ray fluorescence (EDX), and X-ray photoelectron spectroscopy (XPS) unambiguously indicated the presence of neodymium metal.

Synthesis of sodium silicate crystals from rice husk ash

The rich husk is an agricultural waste of rice cultivation worldwide, which is highly rich in amorphous silica. Rice husk obtained from Dagiri was pyrolyzed at 750?C to give white ash (RHA) which was further treated with acid (ARHA). The ash was reacted with sodium hydroxide at 90?C for 2.5 h to produce sodium silicate crystals. Sodium silicate synthesized in the study was characterized for some physicochemical parameters. Their structural and morphological properties were assessed using a Fourier transform infra-red spectrophotometer (FTIR), X-ray diffractometer (XRD) and scanning electron microscope (SEM). The mineralogical composition of the ash and sodium silicate was investigated with energy-dispersive X-ray fluorescence (EDXRF) spectrometer. The sodium silicate produced has a melting point of 61?C, pH of 12.03 and appeared as brownish?white to clear-white in colour. The RHA and ARHA from XRD investigation showed patterns which match the mineral phase cristobalite, while that of the sodium silicate XRD patterns match the mineral heptahydrate disodium trioxosilicate as the most dominant phase. Rietveld refinement of the XRD pattern for the sodium silicate gave Rwp = 12.81, Rexp = 5.55, ?2 = 5.3274 and GoF = 2.3081 against a dual phase analysis. The crystals synthesized are suitable for use in cosmetic formulations.

Total-reflection X-ray fluorescence determination of thorium and uranium in the presence of interfering elements in solid geological objects of natural and technogenic origin

The insufficient spectral resolution of the energy-dispersive total-reflection X-ray fluorescence (TXRF) complicates the U and Th Lα lines using for the quantitative determination of low concentrations of these elements in natural solid samples.

CONTRIBUTIONS TO THE STUDY OF HEAVY METALS POLLUTING FROM THE ENVIRONMENT, BY ATOMIC SPECTROMETRY

"In this scientific work are presented a part of the results included in the thesis entitled "Contributions to the study of heavy polluting elements from the environment by atomic spectrometry" which includes the innovative contributions to the study of the distribution of heavy metals in acacia leaves collected from Dâmbovița county and neighboring counties and the distribution of heavy metals from surface and deep soil collected from the main oil parks in Dâmbovița county. In the analysis of heavy metal concentrations in the studied samples, the spectrometric techniques were used: Atomic Absorption Spectrometry (AAS) and Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF), which were successfully optimized and provided valuable information used in following studies, to assess degree of heavy metal pollution of the environment. These methods were used in a complementary way with the biomonitoring technique in order to have as complete information as possible of the elemental composition of the analyzed samples."

Nickel Nanoparticles Anchored on Bentonite Clay for Methane Decomposition with Ordered Carbon as a Product

Catalysts were synthesized with Ni and bentonite clay, without previous treatment, through wet impregnation with 5, 10 and 20% of Ni (m/m). They were characterized by energy dispersive X-ray fluorescence spectrometry (EDX), X-ray diffraction (XRD), temperature-programmed reduction (TPR), thermogravimetric analysis (TGA), adsorption and desorption of N2 at 77 K, and transmission electron microscopy (TEM). The catalytic activity in relation to the methane conversion reaction was evaluated at 500 °C for 0.5 h. The addition of 10 and 20% of nickel to the clay led to a disordered bentonite structure, characterized by the disappearance of the 001 reflection on the X-ray diffractograms, with a consequent increase in the interaction between nickel oxide and clay (TPR). All catalysts synthesized showed catalytic activity in relation to the conversion of methane to form ordered carbon. The catalyst with 20% of nickel had the highest activity, with 74% of methane conversion.

Assessment of heavy metals in fish and sediments from river Mtakuja in the vicinity of a gold mine in Tanzania

Concentrations of heavy metals namely Cr, Fe, Cu, Zn, As, Cd and Pb in African Sharptooth Catfish (clarias gariepinus) and sediment from river Mtakuja Tanzania were analyzed using the Energy Dispersive X-ray Fluorescence spectrometry technique. 32 samples from fish and sediment were investigated. The results show that the concentration of heavy metals was higher in upstream areas than in the downstream area. The concentration of Fe of 428.5 mg/kg in catfish from the upstream area was about 2 times 243.8 mg/kg obtained from the same fish in the downstream area. Similar cases observed for sediments with Fe concentration of 127626.9 mg/kg from upstream that was about 6 times higher than that of 21460.3 mg/kg from downstream area. The concentration of 44.8 mg/kg for Cu in the upstream area sediment was also about 2 times higher than 23.2 mg/kg in the downstream area sediment, while for as the concentration of 13.2 mg/kg was measured in the upstream, which is which is more than 5 times 2.5 mg/kg measured in downstream. The concentration of Cr in the catfish was 17.6 mg/kg which is higher than the permissible limit values of 0.8 mg/kg set by the European Commission (EC), 0.2 mg/kg set by the Food and Agricultural Organization (FAO) and 0.15 mg/kg the World Health Organization (WHO) limit. Moreover, the concentration of Cd was 3.0 mg/kg, which is above the permissible level of 0.2 mg/kg recommended by the EC and WHO. A positive correlation exists between the Cu, Pb, Fe and Cd concentration found in sediments and fish samples. The results show that the river Mtakuja is polluted by mining waste, domestic and agrochemical activities. This suggest that, there is a need for regular monitoring of heavy metal in river Mtakuja in order to monitor and protect aquatic organisms and health of benefactors of this river.